Method of manufacturing light emitting device including light emitting element and wavelength converting member

ABSTRACT

A method of manufacturing a light emitting device includes steps of preparing a light emitting element; preparing a wavelength converting member; and bonding the light emitting element and the wavelength converting member to each other using a surface activated bonding technique.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This application is a continuation of U.S. application Ser. No.13/639,759, filed Oct. 5, 2012, which is a National Stage ofPCT/JP2011/058586, filed Apr. 5, 2011 which claims priority to JapaneseApplication No. 2010-089267, filed Apr. 8, 2010 the disclosures of whichare hereby incorporated by reference in their entirety.

BACKGROUND

1. Technical Field

The present invention relates to a light emitting device in which alight emitting element and a wavelength converting member are bonded,and a method of manufacturing the light emitting device.

2. Description of Background Art

Conventionally, there has been proposed is a light emitting devicecapable of emitting light of mixed color, by combining light from an LEDchip which serves as a light emitting element and light from afluorescent material which served as a wavelength converting member. Forexample, Patent Literature 1 describes that a “nucleation layer” made ofGaN is grown on a growth substrate made of sapphire, and the “nucleationlayer” and a “ceramic phosphor” are bonded at high temperature and highpressure.

CONVENTIONAL ART DOCUMENT Patent Literature

Patent Literature 1: JP2006-352085A

SUMMARY OF THE INVENTION Disclosure of Invention Problem to be Solved bythe Invention

However, there has been a problem that, in the light emitting devicedisclosed in Patent Literature 1, the “growth substrate” made ofsapphire and the “nucleation layer” made of GaN are merely thermallycompressed and the bonding strength was weak. It is undesirable becauseweak bonding strength may results in detachment of the growth substrateand the nucleation layer during use.

Accordingly an object of the present invention is to provide a lightemitting device having strong bonding strength between the lightemitting element and the wavelength converting member.

Means to Solve the Problems

A light emitting device of an embodiment of the present inventionincludes a light emitting element and a wavelength converting memberbonded with each other. Particularly, the light emitting element has,from the wavelength converting member side, a first region and a secondregion, the wavelength converting member has, from the light emittingelement side, a third region and a fourth region, the first region hasan irregular atomic arrangement compared with the second region, thethird region has an irregular atomic arrangement compared with thefourth region, and the first region and the third region are directlybonded.

According to an embodiment of the present invention, the light emittingelement includes a substrate having the first region and the secondregion and a semiconductor stacked layer portion formed on thesubstrate. The wavelength converting member has a support member whichhas the third region and the fourth region and a fluorescent materialwhich is contained in the support member.

Further, according to an embodiment of the present invention, thesubstrate is made of sapphire and the support member is made of aluminumoxide.

A method of manufacturing a light emitting device according to anembodiment of the present invention includes a step of preparing a lightemitting element, a step of preparing a wavelength converting member,and a step of bonding the light emitting element and the wavelengthconverting member by using a surface activated bonding technique.

It is preferable that the light emitting element has a substrate made ofsapphire and a semiconductor stacked portion formed on the substrate,the wavelength converting member has a support member made of aluminumoxide and a fluorescent material contained in the support member, andthe substrate and the support member are bonded in the bonding step.

Effect of the Invention

According to the present invention as described above, a light emittingdevice having strong bonding strength between the light emitting elementand the wavelength converting member can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating a cross section of a light emittingdevice according to the present invention.

FIG. 2 is an enlarged view of the region of FIG. 1 inside the brokenlines.

FIG. 3A(a) is a cross-sectional view illustrating a light emittingelement preparation step of preparing a light emitting element 10 in amethod of manufacturing a light emitting device according to anembodiment of the present invention, and FIG. 3A(b) is a cross-sectionalview illustrating a wavelength converting member preparation step ofpreparing a wavelength converting member 20.

FIG. 3B is a cross sectional view illustrating a step of activating thebonding surface in a method of manufacturing a light emitting deviceaccording to an embodiment of the present invention.

FIG. 3C is a cross-sectional view illustrating a bonding step of amethod of manufacturing a light emitting device according to anembodiment of the present invention.

DETAILED DESCRIPTION

The embodiments of the present invention will be described below withreference to the accompanying drawings. The embodiments are intended asillustrative of a light emitting device to give a concrete form totechnical ideas of the present invention, and the scope of the inventionis not limited to those described below. Particularly, the sizes,materials, shapes and the relative positions of the members described inexamples are given as an example and not as a limitation to the scope ofthe invention unless specifically stated. The sizes and the positionalrelationships of the members in each of the drawings are occasionallyshown exaggerated for ease of explanation. Members same as or similar tothose of this invention are assigned the same reference numerals anddetailed description thereof will be omitted.

In a light emitting device according to the present embodiment, a lightemitting element 10 and a wavelength converting member 20 are bonded.FIG. 1 is a cross-sectional view in a direction perpendicular to a lightemission observation surface of a light emitting device according to anembodiment. FIG. 2 is an enlarged view of the region of FIG. 1 insidethe broken line. In a light emitting device according to the presentembodiment, a light emitting element 10 has, as shown in FIG. 1 forexample, a substrate 11 made of sapphire and a semiconductor stackedlayer portion 12 formed on the substrate 11, and a p-electrode 13 and ann-electrode 14 formed on the semiconductor stacked layer portion 12. Thewavelength converting member 20 is made of a base member (supportmember) which serves as a base and a fluorescent material contained inthe base member. In the present embodiment, the substrate 11 of thelight emitting element 10 has, from the wavelength converting member 20side, a first region 11 a and a second region 11 b, and the wavelengthconverting member 20 has, from the light emitting element 10 side, athird region 20 a and a fourth region 20 b. In the substrate 11, thefirst region 11 a has an irregular atomic arrangement compared with thesecond region 11 b, and in the wavelength converting member 20, thethird region 20 a has an irregular atomic arrangement compared with thefourth region 20 b. The first region 11 a and the third region 20 a aredirectly bonded and thus the light emitting element 10 and thewavelength converting member 20 are bonded.

As described above, in the present specification, the term “first region11 a” indicates a region directly in contact with the wavelengthconverting member 20 in the light emitting element 10. Also, the term“second region 11 b” indicates a region abutting (directly in contactwith) the “first region 11 a” in the light emitting element 10. In asame manner, the term “third region 20 a” indicates a region of thewavelength converting member 20 which is directly in contact with thelight emitting element 10. Also, the term “fourth region 20 b” indicatesa region of the wavelength converting member 20 which is abutting the“third region 20 a.” As described above, the first region 11 a having anirregular atomic arrangement compared with the second region 11 b, andthe third region 20 a having an irregular atomic arrangement comparedwith the fourth region 20 b are directly in contact with each other andbonded to form a bonded interface X, and the second region 11 b and thefourth region 20 b are respectively spaced apart from the bondinginterface X. In the present invention, the first region 11 a and thesecond region 11 b (the third region 20 a and the fourth region 20 b)are abutted to each other, but the first region and the second regionhave the same composition. Thus, in the case where the members havingdifferent compositions are adjacent to each other, they are notindicated as the first region and the second region as in the presentinvention. More specifically, in the light emitting element having asapphire substrate and an abutting semiconductor layer, there is no casewhere the semiconductor layer is indicated as the first region and thesapphire substrate is indicated as the second region. That is, the firstregion 11 a and the second region 11 b (the third region 20 a and thefourth region 20 b) in the present specification are fundamentally asingle member with the same composition, but a part of the member isindicated as the first region and a different part of the same member isindicated as the second region. Whether a part belongs to a certainmember can be determined, for example, through a cross-sectionalobservation at atomic level by high-resolution transmission electronmicroscopy or through a comparison of composition from elementalanalysis.

Accordingly, the light emitting element 10 and the wavelength convertingmember 20 can be firmly bonded. Although the reason is not clear, it isconsidered that the first region 11 a and the third region 20 a as awhole is capable of absorbing a strain developed between the lightemitting element 10 and the wavelength converting member 20. Forexample, in the case where the light emitting element 10 and thewavelength converting member 20 are directly bonded through thermalcompression, a strain may occur between the light emitting element 10and the wavelength converting member 20 due to differences in thelattice constant or in the thermal expansion coefficient. As describedabove, enhancing of the bonding strength between the light emittingelement 10 and the wavelength converting member 20 by way of thermalbonding has a limitation. However, it is thought that making the atomicarrangement of the first region 11 a and the third region 20 a which areadjacent to the bonding interface X irregular than that of the secondregion 11 b and the fourth region 20 b enables to efficiently absorb thestrain due to the difference in the lattice constant, the thermalexpansion coefficient, or the like, and thus, the bonding strength isimproved. It is also thought that a high unevenness in the atomicarrangement (preferably in an amorphous state which is in anon-equilibrium metastable state), anisotropic nature due to the crystalstructure lessens and “weak” structures such as brittleness, crystalstructure, and/or lattice defect which is attributed to the anisotropicnature disappears, and thus the bonding strength can be enhanced. Also,for example, in the case where the light emitting element 10 and thewavelength converting member 20 are bonded through an adhesive agentmade of a resin, strain may occur at each interface, because a resin hasa relatively large thermal expansion. In contrast, the light emittingdevice according to the present embodiment does not require a resin tobe interposed, so that a stronger bonding can be achieved.

Further, strain at the bonding interface X can be reduced through thefirst region 11 a and the third region 20 a, so that generation ofstress in the fluorescent materials around the bonding interface X canbe suppressed. The wavelength converting member 20 contains afluorescent material, so that stress associated with heat generation inthe fluorescent material tends to occur. Generation of stress in thefluorescent material may cause an increase in the half bandwidth of theemission spectrum and decrease in the luminous flux, and thusundesirable. However, according to the present embodiment, an adverseinfluence of the strain on the fluorescent material can be reduced. Inthe present invention, the light emitting element 10 and the wavelengthconverting member 20 are directly bonded. Therefore, compared with thecase where the light emitting element 10 and the wavelength convertingmember 20 are connected by an adhesive agent made of a resin whichinherently has a poor thermal conductivity, it is also possible that theheat generated in the wavelength converting member 20 can be efficientlyreleased to the light emitting element 10 side. With this arrangement, astrain generated in the bonding surface X can be further reduced.

Further, directly bonding the light emitting element 10 and thewavelength converting member 20 enables to reduce the number of theinterfaces which reflect light (or totally reflect light depends on theangle of incidence) to one, and thus enables to improve the extractionof light as a whole device. For example, in the case where an adhesivemade of a resin in interposed between the light emitting element 10 andthe wavelength converting member 20, a sum of two interfaces (aninterface between the light emitting element and the adhesive agent andan interface between the wavelength converting member and the adhesiveagent) exist. On the other hand, in the case where the light emittingelement 10 and the wavelength converting member 20 are directly bonded,only one interface (interface between the light emitting element 10 andthe wavelength converting member 20) exists. Therefore, compared to theformer, the latter is capable of decrease the optical loss. Also, a useof an adhesive agent made of a resin results in a high reflectance atthe interface due to a large difference in the refractive indicesbetween the inorganic materials constituting the substrate and the resinwhich is an organic material. In contrast, the present invention iscapable of reducing the difference in the refractive indices between thesubstrate 11 which constitutes a part of the light emitting element andthe wavelength converting member 20, and thus reflection at theinterface can be reduced.

The first region 11 a or the third region 20 a, or the both regions arepreferably made of amorphous having higher atomic irregularity, and morepreferably in a metastable, non-equilibrium amorphous state. With thisarrangement, the strain between the light emitting element 10 and thewavelength converting member 20 can be more efficiently prevented,anisotropy due to crystal structure can be further reduced, crystalstructures and/or lattice defects can be eliminated, and the bondingstrength can be further enhanced.

Either the second region 11 b or the fourth region 20 b (preferably theboth) may be preferably made of a polycrystal or a single crystal, morepreferably made of a single crystal. The second region 11 b and/or thefourth region 20 b being a polycrystal or a single crystal (particularlya single crystal) is thought to induce the strain therebetween. Thus,the present embodiment is particularly effective in such a state.

From a view point of reducing the strain, the first region 11 a and thethird region 20 a are preferably disposed on substantially the entirearea of the bonding interface X. However, in the present invention, theregion to which the first region 11 a and the third region 20 a aredirectly bonded may be a part of the bonding interface X, and which isin the scope of the present invention as long as it exerts the effectsas described above.

The first region 11 a and the third region 20 a respectively have athickness of preferably 1 nm to 20 nm, further preferably 2 nm to 10 nm.With this arrangement, the effect of reducing the strains can besufficiently obtained, so that the bonding strength can be enhanced.Further, making the first region 11 a and the third region 20 a with anirregular atomic arrangement may adversely affect the extraction oflight, but in the range as described above, the thickness of the portionof optical attenuation can be substantially reduced, and thus opticalloss can be reduced.

For the light emitting device according to the present embodiment, thelight emitting element 10 is not limited and a known light emittingelement can be used. For example, as shown in FIG. 1, the light emittingelement 10 may be include a substrate 11, a semiconductor stacked layerportion 12 disposed on the substrate 11, and a pair of electrodes 13 and14 disposed on the same surface side of the semiconductor stacked layerportion 12. For the substrate 11, sapphire, GaN, or the like, can beemployed. For the semiconductor stacked layer portion 12, a stackedlayer of a plurality of nitride semiconductor layers (AlInGaN), or thelike, can be employed. In view of extraction of light, the wavelengthconverting member 20 side is preferably used as the viewing side.

In the case where sapphire is used as the substrate 11 of the lightemitting element 10, it is preferable that the support member, which tobe described later, of the wavelength converting member 20 is made ofaluminum oxide and that the sapphire and the aluminum oxide are directlybonded. That is, the first region 11 a and the second region 11 b areformed in the sapphire and the third region 20 a and the fourth region20 b are formed in the aluminum oxide, and the first region 11 a and thethird region 20 a are directly bonded.

With this arrangement, the same compositional elements can be used forthe substrate and the support member, so that bonding strength of theboth can be further enhanced. Further, the refractive indices of thesubstrate and the support member can made substantially the same, sothat the total reflection of light at the interface can be reduced andlight extraction of the light emitting device can be improved. Althoughthe effects described above can be achieved regardless of the crystalstructures of aluminum oxide which constitutes the support member, thecrystal structure of aluminum oxide may be preferably a polycrystal or asingle crystal, more preferably a single crystal (sapphire). With thisarrangement, a similar or the same structure as the substrate made ofsapphire can be obtained and therefore the effects as described abovecan be easily obtained.

In another variant example, in a light emitting element 10, afterforming a semiconductor stacked layer portion on a substrate, a bondingsubstrate such as Si is adhered to the semiconductor stacked layerstructure, then the initial substrate is removed and the bondingsubstrate and a wavelength converting member may be bonded. Further,regardless of whether a substrate is used, the semiconductor stackedlayer portion and the wavelength converting member can be bonded. In thecase where the semiconductor stacked layer portion and the wavelengthconverting member are bonded, one semiconductor layer at the most outerside of the semiconductor stacked layer portion to be bonded to thewavelength converting member has, from the wavelength converting memberside, a first region and a second region, and the first region has anirregular atomic arrangement compared with the second region.

For the light emitting device according to the present embodiment, thewavelength converting member 20 is capable of converting light from thelight emitting element 10 into light having different wavelengthdistribution, and the material thereof is not limited, and a knownmaterial can be used. The wavelength converting member 20 may be afluorescent material, or may includes a fluorescent material and asupport member which support the fluorescent material. In the case wherethe wavelength converting member 20 includes a fluorescent material anda support member, for example, the wavelength converting member 20 is aneutectic of a fluorescent material and a support member formed by usingan irreversible coagulation technique, or the wavelength convertingmember 20 is integrally formed by sintering a fluorescent materialpowder and a material powder of the support member.

The fluorescent material is not limited and a known fluorescent materialcan be used. For example, a YAG (yttrium aluminum garnet) basedfluorescent material and/or a TAG (terbium aluminum garnet) basedfluorescent material may be used. With this arrangement, for example, bymixing blue emission from the light emitting element 10 and yellowemission from the fluorescent material, white light can be emitted.

The support member is not limited and a known support member can beused. For example, aluminum oxide, aluminum nitride, YAG (non-luminous,because an activator is not contained), and/or yttrium oxide can beused.

The fluorescent material has a base member and an activator, and thesupport member is preferably made of the same materials as the basemember. With this arrangement, the difference in the refractive indicesbetween the fluorescent material and the support member can besubstantially eliminated. As a result, total reflection of light at theinterface between the support member and the fluorescent material can besubstantially reduced, and the light extraction efficiency as the entirelight emitting device can be improved. Further, employing the samematerials for the support member and the base member enables to reducethe stress generated in the fluorescent material. For example, a YAG(non-luminous, because an activator is not contained) can be used forthe support member and a so-called YAG-based fluorescent material withcerium as the activator and a YAG as the base member, can be used forthe fluorescent material.

As shown in FIG. 3, a method of manufacturing a light emitting deviceaccording to an embodiment of the present invention includes a step ofpreparing a light emitting element 10 (see FIG. 3A(a)), a step ofpreparing a wavelength converting member 20 (see FIG. 3A(b)), and abonding step for bonding the light emitting element 10 and thewavelength converting member 20 (see FIGS. 3B and 3C).

In the present embodiment, the term “surface activated bondingtechnique” refers to that carrying out sputter etching by using ionbeams or plasma on a bonding surface of a light emitting element 10 anda wavelength converting member 20 to activate both the surfaces to bebonded, then directly bond the light emitting element 10 and thewavelength converting member 20 at the bonding surfaces.

Accordingly, the light emitting element 10 and the wavelength convertingmember 20 can be firmly bonded. This is considered as the result ofsputter etching, the first region 11 a and the third region 20 a areformed and the both absorb the strain between the light emitting element10 and the wavelength converting member 20 in an integrated manner (seeFIG. 2). The details are as described above and will not be repeatedhere.

Generally, a light emitting element is fabricated in such a manner thata column-shaped ingot of sapphire is thinly sliced to obtain disk-shapedwafers, and on each wafers, a plurality of semiconductor stacked layerportion as 12 are formed and then divided into each of the lightemitting elements. In the present invention, at the time of bonding thelight emitting element 10 and the wavelength converting member 20 byusing a surface activated bonding technique, prior to dividing into eachof the light emitting elements, a wafer on which a plurality ofsemiconductor stacked layer portions 12 are formed and the wavelengthconverting member 20 may be bonded, or after dividing into each of thelight emitting elements, the wavelength converting member 20 is bondedto each of the light emitting element 10, by using a surface activatedbonding technique. However, in the case where the light emitting element10 and the wavelength converting member 20 are bonded by using a surfaceactivated bonding technique, the use of the light emitting elements 10which are already divided into single units has an advantage asdescribed below (in the present specification, not only the state ofindividually divided unit but also the previous state of the wafer arealso referred to a “light emitting element.” That is, generally, thelight emitting elements formed on a wafer have different properties suchas the peak wavelength and/or optical output power depending on theirlocations on the wafer. However, such light emitting elements obtainedby dividing the wafers can be grouped together by selecting the same orsimilar properties, and appropriate wavelength converting members 20 canbe selected and bonded respectively thereto. Examples of specific stepsinclude arranging a plurality of light emitting elements having similarproperties on a single adhesive sheet (first step), bonding each of thelight emitting elements arranged on the adhesive sheet with a singlesheet of a wavelength converting member by using a surface activatedbonding technique (second step), removing the adhesive sheet (thirdstep), and cutting the wavelength converting member as needed to obtainindividual light emitting devices (fourth step).

Heating the light emitting element may result in deterioration of theelectrodes and/or the light emitting layer, but a surface activatedbonding technique is not necessarily heated. Thus, the light emittingelement 10 and the wavelength converting member 20 can be bonded withoutdeteriorating the properties of the light emitting element. Althoughaccording to the materials and construction of the electrodes and thematerial and the construction of the semiconductor stacked layerportion, the range of temperature to perform a surface activated bondingtechnique may be preferably 0° C. to 300° C., more preferably 0° C. to200° C., further preferably 0° C. to 100° C., yet further preferably 0°C. to 50° C. With this arrangement, a firm bonding can be achievedwithout undermining the properties of the light emitting element.

The bonding surfaces of the light emitting element 10 and the wavelengthconverting member 20 may have a surface roughness (Ra) of 10 nm or less,more preferably 5 nm or less, and further preferably 1 nm or less.Accordingly, the light emitting element 10 and the wavelength convertingmember 20 can be easily and firmly bonded.

Though, depending on the material and state of the bonding surface ofthe light emitting element 10 and the bonding surface of the wavelengthconverting member 20, bonding of the both by using a surface activatedbonding technique may be difficult. Even in such a case, forming abonding member capable of bonding to the both on one or both of thelight emitting element 10 and the wavelength converting member 20enables bonding of the both. For example, with a use of surfaceactivated bonding technique, a glass (including a fluorescent material)is difficult to be bonded to the sapphire substrate of the lightemitting element. For this reason, a bonding member such as aluminumoxide is formed on the glass surface by using sputtering or the like,which enables bonding of aluminum oxide and the sapphire substrate byusing a surface activated bonding technique. In this case, thewavelength converting member 20 is made of a fluorescent material, asupport member (glass) and a bonding member (aluminum oxide), and thebonding member has, from the light emitting element side, a third regionand a fourth region, and the third region has an irregular atomicarrangement compared with the fourth region.

Example 1 Light Emitting Element 10

Respective layers of nitride semiconductor were grown on a sapphiresubstrate 11 to form a semiconductor stacked layer portion 12. Ann-electrode 13 and a p-electrode 14 were formed on a part of apredetermined portion of the semiconductor stacked layer portion 12. Thesapphire substrate in a wafer state was ground to reduce the thicknessto about 85 micrometers. Further, using a CMP (Chemical MechanicalPolishing) technique, scratch marks left by the polishing are removedand the surface was smoothed to an Ra of 1 nm or less. The lightemitting element in a wafer state obtained as described above was cutout by scrubbing to obtain individual light emitting elements 10. In thepresent example, each light emitting element 10 of 1 mm long and 1 mmwide in a plan view was formed.

Characterization such as voltage characteristic, wavelength, and leakagewere carried out on each of the light emitting elements 10 and the lightemitting elements 10 were sorted into groups on the basis of theircharacteristics. The light emitting elements 10 of respective groupswere arranged on a respective adhesive sheet at an interval of 200micrometers with each other.

(Wavelength Converting Member 20)

A wavelength converting member 20 formed by using an irreversiblecoagulation technique is prepared. The wavelength converting member 20of the present example was made of a sapphire (support member)containing YAG (fluorescent material). In conformity with thechromaticity of a desired white LED (light emitting device), thewavelength converting member 20 was ground and polished to a desiredthickness. Next, in order to further smooth the surface which is toserve as the bonding surface, polishing and CMP were carried out. Atthis time, due to the difference in the polishing rate, the sapphireportion becomes in a protruded shape and the YAG portion becomes arecesses shape, but in the present example, the difference in the heightof the sapphire portion and the YAG portion is adjusted to 10 nm orless. The surface roughness of the YAG and the sapphire at the bondingsurface were respectively adjusted to the Ra of 2 nm or less.

(Surface Activated Bonding)

On the upper part of the bonding chamber, a plurality of the lightemitting elements 10 were arranged on an adhesive sheet so that thesapphire substrates 11 which serve as the bonding surfaces locate to theunderside. At the lower part of the bonding chamber, the wavelengthconverting member 20 was placed so that its bonding surface locates tothe upper side.

The bonding chamber was vacuumed to 8.0×10⁻⁶ Pa or less. Then, using twofast ion beam (FAB: fast atom beam) guns, Ar ion beam was irradiatedrespectively on the upper and lower samples. Ar beam was irradiated witha flow rate of 40 scm, an acceleration current of 100 mA, and for 180seconds. Then, the upper and lower samples were bonded within a shorttime of 30 seconds or less. At this time, a pressure of 0.2 N/mm² ormore was applied on the samples for 30 seconds. The bonded sample wastaken out from the bonding chamber and the adhesive sheet was removedfrom the sample.

(Chip Separation and Others)

A plurality of the light emitting elements 10 arranged on a single sheetof the wavelength converting member 20 are divided by dicing to obtainindividual units of the light emitting devices. One of the lightemitting device was mounted in a flip chip manner on a circuit boardhaving electrodes and covered with a white resin made of titaniaparticles dispersed in a silicone resin, except for the upper surface ofthe wavelength converting member 20 which serve as the light emittingsurface.

The light emitting devices obtained in the present example wereconfirmed to have approximately twice as much improvement in the dieshear strength (bonding strength) as compared to the devices ofComparative Example. Further, compared to comparative Example, anapproximately 10% improvement in the luminous flux was confirmed.

Comparative Example

The light emitting devices having substantially the same structure as inExample 1 were fabricated except that the sapphire substrate and thewavelength converting member were bonded by using an adhesive materialmade of a silicone resin.

INDUSTRIAL APPLICABILITY

The light emitting device according to an embodiment of the presentinvention can be used, for example, for lighting devices and displaydevices.

DENOTATION OF REFERENCE NUMERALS

-   10 light emitting element-   11 substrate-   11 a first region-   11 b second region-   12 semiconductor stacked layer portion-   13 p-electrode-   14 n-electrode-   20 wavelength converting member-   20 a third region-   20 b fourth region

What is claimed is:
 1. A method of manufacturing a light emitting devicecomprising steps of: preparing a light emitting element; preparing awavelength converting member; and bonding the light emitting element andthe wavelength converting member to each other using a surface activatedbonding technique.
 2. The method of manufacturing a light emittingdevice according to claim 1, wherein the light emitting elementcomprises: a substrate, and a semiconductor stacked layer portion formedon the substrate, wherein the wavelength converting member comprises: asupport member, and a fluorescent material contained in the supportmember, and wherein, in the step of bonding, the substrate and thesupport member are bonded to each other.
 3. The method of manufacturinga light emitting device according to claim 2, wherein the fluorescentmaterial comprises one of an yttrium aluminum garnet based fluorescentmaterial and a terbium aluminum garnet based fluorescent material. 4.The method of manufacturing a light emitting device according to claim1, wherein a temperature to perform a surface activated bondingtechnique is set not less than 0° C. nor more than 300° C.
 5. The methodof manufacturing a light emitting device according to claim 1, wherein atemperature to perform a surface activated bonding technique is set notless than 0° C. nor more than 200° C.
 6. The method of manufacturing alight emitting device according to claim 1, wherein a temperature toperform a surface activated bonding technique is set not less than 0° C.nor more than 100° C.
 7. The method of manufacturing a light emittingdevice according to claim 1, wherein bonding surfaces of the lightemitting element and the wavelength converting member have a surfaceroughness (Ra) of 10 nm or less.
 8. The method of manufacturing a lightemitting device according to claim 1, wherein bonding surfaces of thelight emitting element and the wavelength converting member have asurface roughness (Ra) of 5 nm or less.
 9. The method of manufacturing alight emitting device according to claim 1, wherein bonding surfaces ofthe light emitting element and the wavelength converting member have asurface roughness (Ra) of 1 nm or less.
 10. The method of manufacturinga light emitting device according to claim 1, wherein a temperature toperform a surface activated bonding technique is set not less than 0° C.nor more than 50° C.